Branch of the United Federation of Planets assigned to the exploration of space and the resulting scientific, diplomatic and defensive duties. Starfleet began as an Earth agency dedicated to space exploration. To this end, Starfleet utilized interstellar starships and eventually built and maintained a network of starbases. The first warp 5 starship, the Enterprise NX-01, was launched in April 2151 and captained by Jonathan Archer. The ship represented humankind's first foray into long-term space travel.